People line up to enter a newly-opened Apple Store in Wangfujing shopping district in Beijing last October. / Andy Wong, AP

by Matt Krantz, USA TODAY

by Matt Krantz, USA TODAY

Apple's stock plunged below $500 on Tuesday as investors worried that the premium prices the gadget maker has enjoyed are under attack amid weaker-than-expected demand for its latest smartphone.

The latest drop in Apple stock, falling to $487 a share, was triggered by news that orders for parts that go into the iPhone 5 have been cut because demand for the phones is weaker than expected, according to a report in The Wall Street Journal. The brutal stock decline, putting it down nearly early 30% from its high, is the latest sign that Apple's untouchable position is under attack as consumers buy products from competitors or don't rush to upgrade to the latest version of an Apple product.

The WSJ report, which cited unnamed people familiar with the matter, said orders for iPhone 5 screens for the January-March quarter are about half what was expected. Orders for other types of components have also been reduced, the WSJ article said. The Journal said it was told Apple notified the suppliers of the order cut last month.

Apple didn't immediately return an e-mail seeking comment Monday.

Meanwhile, analysts aren't all that upbeat on Apple's earnings announcement, due later this month. Analysts expect the company to earn $13.46 a share in the December 2012 quarter, down 3% from the $13.87 a share it earned in the December quarter of 2011, says S&P Captial IQ. And some analysts think those expectations might be too high.

Apple's reputation as a fast-growth company appears to be waning. Apple has missed earnings estimates in three of the past five calendar quarters, including the past two straight, says FactSet. And Apple might come up short on revenue forecasts on weak iPad demand, says Mizuho Securities analyst Abhe Lamba in a report to clients.

Apple's woes come as the company has been facing increased competition from Samsung Electronics and other makers of smartphones that run Google's Android operating system. Meanwhile, shares of Nokia, the Finnish maker of the Lumia handset that runs the Windows Phone operating system, have rocketed 17% this year.

South Korea's Samsung, which sells Android-based phones at various price points, has already overtaken Apple as the world's largest smartphone vendor by market share. Over the weekend, Samsung revealed global sales of their line of Galaxy S smartphones topped 100 million. The Galaxy S III sold particularly well, topping 40 million in sales in seven months.

Android devices accounted for 75% of smartphone shipments the three months ended in September, up from 58% at the same time in 2011, according to research firm IDC. The iPhone's share stood at 15% in September, up from 14% the previous year.

Google says more than 500 million Android devices have been activated since the software's release four years ago. By comparison, Apple had sold about 271 million iPhones through last September.